Lots of people are linking to this excellent video (presentation and screencast) by Sean Kelly at JPL (380 megabyte, 30+ minutes, worth it):
Watch it all the way through. Wow.
It’s a little over-the-top in its J2EE example; but the disparity is still stark… and near to my heart as we have a time tracking web application in development.
But I think he stopped short of a fundamental point: that the benefits of dynamic languages, XML-free convention over configuration, fast turnaround, etc. are not specific to GUIs or web applications; he experienced them there and showed them there, but as far as I can tell the same issues and benefits apply equally to the non-GUI tiers of a system.